Abstract

This is a non-final version of the article published in final form in Maier, K. J., & Al'Absi, M. (2017). Toward a biopsychosocial ecology of the human microbiome, brain-gut axis, and health. Psychosomatic medicine, 79(8), 947-957.
OBJECTIVE: Rapidly expanding insights to the human microbiome and health suggest that
Western medicine is poised for significant evolution, or perhaps revolution – this while the field
continues on a trajectory from reductionism to a biopsychosocial (BPS) paradigm recognizing
biological, psychological, and social influences on health. The apparent sensitivity of the
microbiota to perturbations across BPS domains suggests that a broad and inclusive framework
is needed to develop applicable knowledge in this area. We outline an ecological framework of
the human microbiome by extending the BPS concept to better incorporate environmental and
human factors as members of a global, dynamic set of systems that interact over time.
METHODS: We conducted a selective literature review across disciplines to integrate
microbiome research into a BPS framework.
RESULTS: The microbiome can be understood in terms of ecological systems encompassing
BPS domains at four levels: (1) immediate (molecular, genetic, and neural processes); (2)
proximal (physiology, emotion, social integration); (3) intermediate (built environments,
behaviors, societal practices); and (4) distal (physical environments, attitudes, and broad cultural,
economic, and political factors). The microbiota and host are thus understood in terms of their
immediate interactions and the more distal physical and social arenas where they exist.
CONCLUSIONS: A BPS ecological paradigm encourages replicable, generalizable,
inter/transdisciplinary research and practices that take into account the vast influences on the
human microbiome that may otherwise be overlooked or understood out of context. It also
underscores the importance of sustainable bio-environmental, psychological, and social systems
that broadly support microbial, neural, and general health.